China could have its first aircraft carrier operational in two years, according to the most senior US military official in the Asia-Pacific region.

Admiral Robert Willard, commander of the US Pacific Command in Hawaii, told a recent US congressional hearing that the Soviet-era carrier Varyag, bought from a Ukrainian shipyard in 1998, would be 'operational around 2012 and likely be used to develop basic carrier skills' after a 10-year refit. His statement is the most specific yet from the Pentagon on Beijing's aircraft carrier ambitions.

Several military analysts and diplomatic military attach?s said the Varyag had recently left dry dock at a Dalian shipyard revealing extensive work to its hull and superstructure. It had also been demagnetised in order to avoid mines. They said they believed the Varyag would almost certainly be kept close to the mainland coast to train pilots and crew until China's first domestically built carriers were completed, possibly as soon as 2015.

It is not yet known whether Varyag's engines have been fully fitted. A full-scale concrete replica of its flight deck and superstructure is near completion next to a technical college in Wuhan , Hubei province.

Willard told the armed services committee of the House of Representatives late last week there was a need for deeper engagement with Beijing amid international doubt that its military modernisation was 'purely defensive' as stated. 'Frank and candid' discussions were needed, he said, but they required 'a stable and reliable US-China military-to-military relationship - a relationship that does not yet exist with the PLA'.

'Over the past few years, China has begun a new phase of military development by beginning to articulate roles and missions for the PLA that go beyond China's immediate territorial concerns, but has left unclear to the international community the purposes and objectives of the PLA's evolving doctrine and capabilities,' Willard said.

An operational Varyag is widely seen as a crucial step on the path to China fulfilling its aim of achieving full blue-water naval capability.

Even if the Varyag is operational in two years, it remains unclear whether China will be able to obtain planes capable of flying from its take-off ramp. While pilots have been in training with Ukrainian advisers, Beijing has yet to complete a deal with Moscow to purchase carrier-capable Su-33 fighters.

Talks have dragged on for four years, with Moscow - wary of having its military technology reverse-engineered - wanting to sell at least 50 planes and China wanting a far smaller number.

China has already obtained an Su-33 prototype from Ukraine for research purposes.

The PLA will also need to perfect theconfiguration of the Varyag's radars, wiring and communications - all highly complicated on a cramped carrier. It will also have to learn to use the ship in tandem with the support ships and submarines vital to its protection.

Andrew Erickson, a China scholar at the US Naval War College, said getting the Varyag operational was merely the start. 'China's refitting of Varyag to make it operational around 2012 seems to be part one of a two-part approach - outfit a foreign-purchased platform to enable basic training, while preparing a more capable [domestically made] platform for higher-level military operations,' he said.

'Some time after 2015, personnel that initially trained on the Varyag could be transferred to China's first indigenous operational carrier.' Whether the home-grown design would be based on the Varyag remained to be seen. Analysts have noted that the ramps used on the Soviet-era carriers limit the type and weight of aircraft that can be deployed compared to flat-deck carriers that use steam catapults, such as American and French carriers.

Xu Guangyu , a Beijing-based retired PLA general, said the Chinese side had yet to reveal a detailed schedule for carrier development. 'I think Admiral Willard's report comes the closest to Beijing's answer because the US is the most experienced aircraft carrier expert.'

Gary Li, a PLA specialist at the London-based International Institute of Strategic Studies, said it was clear that PLA officials were well aware of the limitations of the Varyag and were still looking at other designs.

'It does seem they've got little option at the moment but to push ahead with the Varyag for training ... it is clear they know just how long a road they have embarked on, so they've got to make a start on integrating all the necessary components,' he said.

'Although carrier technology is very old, it is still extremely complex to acquire from scratch. Even the welding techniques to withstand such stresses are closely held secrets.'

The 67,500-tonne Varyag was partially completed in a Ukrainian shipyard when the Soviet Union collapsed. Stripped of technology, the hull and superstructure were sold to Beijing for US$20 million in 1998. China later paid extra for the blueprints.

The then-rusting hulk of the ship was towed to China via Macau, prompting early speculation that it might be used for a casino.

Additional reporting by Minnie Chan

Projecting power

The first aircraft carrier to be launched by the PLA Navy will be a refitted Russian vessel of the Admiral Kuznetsov class, and it is likely to be carrying either Russian-made Su-33 jets or domestically developed J-10 fighters